What's the simplest way to wrap extruded text around a cylinder?
Try using a Curve modifier.


Add curve circle (ShiftA> Curve Circle) and set the radius as desired in the Redo menu (at the bottom of the Tool Shelf):


Add the text object (ShiftA> Text) and type in your text (Tab> Edit mode):


Add a curve modifier to the text object in Properties > Modifiers, and set the Object to be your curve circle:


Rotate the text object 90 degrees on the X axis (RX90) and then scale by -1 again on the X (SX-1):

 
Increase the Extrude value in Properties > Text > Geometry to give the text some thickness:



Optionally increase the Depth and Resolution values for Bevel to round the edges a bit.


Result: